Warm air furnace



Jan. 18, 1944. R BM 2,339,254

WARM AIR FURNACE Filed Jan. 9, 1943 I INVENTOR BY fP/CHARD' 5. D/LL ATTORNEY ?atentefi .Fan. 18, l

UNITED STATES PATENT o en Richard s. Dill, New Bern, N. .c.,

assignor to the Government of the UnitedStates, as represented by the Secretary of Commerce 4 Claims.

, The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment to me of any royalty thereon in accordance with the provisions of the act of April 30, 1928 (Ch. 460, 45 Stat. L. 467) This invention relates to warm air heating furnaces and has for its object to provide an arrangementfor utilizing the heat from a furnace to furnish mechanical power for increasing the air flow to the furnace.

With this object in view, the invention consists of thecombination of the return air duct to the furnace and a hot air engine so arranged in connection with the furnace that the engine is operated by the heat of the furnace and the pdwer supplied is utilized to operate a blower for forcing air to the iumace to be heated therein and distributed through ducts to various parts of a house.

A further object of the invention is to utilize the mechanical power supplied by the hot air engine for any appropriate purpose, either separately or in connection with the blower.

with these objects in view, the invention consists of the arrangement of the hot air engine in connection with a hot air furnace and thereturn air duct thereof, and also in certain details of construction, all of which will first be fully de-' scribed and afterwards in the appended claims.

Referring to the accompanying drawing:

The figure is a diagrammatic view illustrating the invention.

In the application of my invention, I prefer to use a hot air engine of the Lehmann type. This specifically pointed out Leh'mann type of engine is fully described in thebook entitled Technical Thermodynamics, Vol. I, by Zeuner and in other references. It is well known to those skilled in the art, and as I lay no claim to originality to the construction of the engine per so, its details have not been illustrated (Granted under the act of March 3, amended April 30, 1928; 37]) 0. G.

I is the hotend 1 of the cylinder of the hot air I engine 8, while the cold end 9 of the cylinder of the hot 'air engine. is disposed within the return air duct 3, the said cold end 9 of the cylinder of the hot air engine 8 being provided with heat radiating fins I0 within the return air duct I so as to more effectually cool the cold end 8 of the engine cylinder by the down draft of cold air passing through the return air duct 3.

Driven by the hot air engine 8 is a pulley l2 and belt I4 leading to the pulley I 3 of the blow- Having thus described the several parts of the invention, its operaiion is a follows: The device being assembled as shown in the drawing. the heat from the fire box 6 of the furnace I, heats the hot end 1 of the cylinder of the engine I, which starts the engine in operation; By reason of the pulleys l2 and I3 and the belt ll, the blower 5 is actuated. This causes an increased circulation of cold air downwardly of the return air duct 3 and into the heating drum 4 of the furnace 'l,. which at the same time absorbs the heat from the'cold end 9 of the cylinder of the hot air engine 8..

The advantages of this arrangement are at once apparent, as by it the usual electric motor] employed to ,drive. the blower is displaced, while the power supplied from the hot air enginefor the same purpose adds nothing to the cost of operation. Additionally, the engine is self regulating,

in the drawing nor described in this speciiica- I tion.

1sReferring to the drawing by reference numera i indicates a warm air furnace of a conventional type. 2 indicates the warm airsupply ducts leading from the furnace 'l, and 3 indicates the return air duct leading to the furnace. Connecting the return air duct 3 to the heated air drum for the furnace I near thebottom thereof is a blower of conventional form.

Connecting with the fire box 8 of the furnace since a brisk fire in the furnace causes the engine to run faster, thus increasing the air flow when more heat is required, and a slower run-:

ning and less air flow when the-fire in the furnace is low. I

It is also obvious that a fan or other accessories may be operated by the engine either separately or in connection with the blowerj.

Having thus described the operation of the invention, I do not wish to limit myself to the exact arrangement of the parts illustrated in the diagrammatic flgureof the drawing, as such may be changed or modified, and. I consider myself clearly entitled to all such changes and modifications as fall within the limit and scope ofthe appended claims.

I claim: 1. The combination with a warm air furnace having a fire box, 'warm air drum, air supply ducts leading from the warm air drum, a cold air return duct and a blower for supplying cold air to the warm air drum, of a hot air engine having the hot end of its cylinder connected to necting the hot air engine with the said blower for driving the blower.

2. The-combination with a warm air furnace having a fire box, warm air drum, an air supply duct leading from the warm air drum, and a cold air duct and a blower for supplyingair-to the warm air drum, of a hot air engine having the hot end of its cylinder connected to the fire box of the furnaceand the cold end of its cylinder disposed within the cold air duct and means connecting the hot air engine with the said blower for driving the blower.

3. In a device for generating power for any appropriate purpose, the combination with a warm air furnace having a fire box, warm air drum, an

path oi circulation of cold air 'nace and the cold end of its cylinder within the cold air duct and-in the path oi! circulation of the cold air air supply duct leading from the warm air drum, and a cold air duct for supplying air to the warm air drum, of a hot air engine having the hot end or its cylinder connected to the fire box of the furnace and the cold end of its cylinder disposed within the cold air duct and in the path of circulation of cold air within the cold air duct.

4. In a device for generating power for any appropriate purpose the combination with a warm air furnace having a fire box, warm air drum, an air supply duct leading from the warm air drum and a cold air duct !or supplyingv air to the warm air drum, 0! a hot air engine having the hot end of its cylinder connected to the furdisposed within the cold air duct.

RICHARD s; DILL. 

